head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Practiced Mastery
Kiting and shooting scripted alien swarms with modest resource management underneath.

Execution · Practiced Mastery
The infamous, glitch-ridden 2006 Sonic reboot where the physics are the real boss.
Alien Breed 2: Assault leans Execution (Practiced Mastery); Sonic the Hedgehog (2006) leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Alien Breed 2: Assault
Twin-stick aim and kiting under swarm pressure decide survival
Sonic the Hedgehog (2006)
Fighting unreliable physics demands constant correction
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Alien Breed 2: Assault
Alien hordes path predictably with no adaptation
Sonic the Hedgehog (2006)
No adaptive opposition
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Alien Breed 2: Assault
Ambush placements are scripted-but-unknown on first run
Sonic the Hedgehog (2006)
Bugs make outcomes partly unpredictable
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Alien Breed 2: Assault
Ammo economy and route knowledge smooth repeat playthroughs
Sonic the Hedgehog (2006)
Learning which routes the jank permits
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.